It's A Small World, Pt. 1 is a Storyline Quest. It comes right after you've added Ant-Man to your Academy. An A.I.M Scientist shows up and offers Scott a chance at redemption by helping stop the Scientist Supreme from destroying the world.
The Robo Dojo (arena)
Quest Dialogue Edit
A.I.M. Scientist: How'd you like a shot at redemption, Scott Lang?
Ant-Man: I'm good. I get those all the time.
A.I.M. Scientist: This is serious. The Scientist Supreme is trying to revive A.I.M. by doing something catastrophic, and you're the only one who can stop it...
Ant-Man: Yeah, I don't know. You seem kind of untrustworthy. Not that I'm judging, I'm just on my way to do some stuff...
A.I.M. Scientist: I'll find you when the time is right.
Ant-Man: Cool, that's really romantic...
Ant-Man: So, what's your thing again? I forgot.
A.I.M. Scientist: A.I.M.'s Scientist Supreme is about to get enough power to destroy us all, and you're the only one who can stop him.
Ant-Man: What's in it for you?
A.I.M. Scientist: I'd like to not be destroyed along with the rest of the world, and now that A.I.M. has disbanded, I'd like a chance to join Avengers Academy.
Ant-Man: That's Fury's department. Did you know he keeps an extra eyepatch in his wallet?
A.I.M. Scientist: We don't have time for this. You need to get to Asgard immediately...
A.I.M. Scientist trying to recruit Ant-Man